Where *do* you draw the line between nutritional supplements and doping? I've been wondering about that since this thread started, here's what WADA (the World Anti-Doping Agency) has to say (for the entire document listing banned substances, go here:
4.3.1 A substance or method shall be considered for inclusion ... if WADA determines that the substance or method meets any two of the following three criteria:
4.3.1.1 Medical or other scientific evidence, pharmacological effect, or experience that the substance or method has the potential to enhance or enhances sport performance.
4.3.1.2 ... the Use of the substance or method represents an actual or potential health risk to the Athlete.
4.3.1.3 WADA's determination that the Use of the substance or method violates the spirit of sport described in the Introduction to the Code.
So, stimulants are out (including ephedrine in high doses), narcotics, marijuana, steroids, hormones like EPO and insulin, masking agents, and other things I've never heard of. Alcohol is OK though. And caffeine and codeine are on WADA's monitoring list so that they can detect "patterns of misuse."

Interesting.